CN102146007A - Method for preparing secondary amine and tertiary amine - Google Patents

Abstract

The invention provides a method for preparing secondary and tertiary amines. Using primary alcohol or secondary alcohol and primary amine or secondary amine as raw materials, in the presence of solvent or non-solvent, heterogeneous bimetallic platinum-tin catalyst Pt-Sn/γ-Al ₂ O ₃ or Pt-Sn/TiO ₂ , A method for preparing secondary or tertiary amines by reacting at 80-200°C for 1-24 hours in a closed reactor. The catalyst is a heterogeneous bimetallic platinum-tin (Pt- _Sn ) catalyst immobilized on the inorganic material γ- _Al2O3 or _TiO2 , the mass percentage of metal platinum is 0.1-10%, platinum and tin The molar ratio is 1:1-1:11, and the catalyst can be recycled. The invention has the characteristics of easy-to-obtain raw materials, simple process, high product yield, no three wastes, and low production cost, and is a method for preparing secondary or tertiary amines with extremely high atom economy and environmental friendliness.

Description

A method for preparing secondary and tertiary amines

technical field

The invention relates to a method for preparing secondary and tertiary amines through catalytic dehydration of primary or secondary alcohols and nitrogen-containing compounds selected from primary or secondary amines through heterogeneous bimetallic platinum-tin catalysts. The method has the characteristics of easy-to-obtain raw materials, simple process, good atom economy, high efficiency and no three wastes.

technical background

Secondary and tertiary amines are important organic synthesis raw materials and intermediates, widely used in medicine, pesticides, food and dye industries and other fields. There are many ways to prepare organic amines, such as the alkylation reaction of halogenated hydrocarbons with ammonia, primary and secondary amines. Although the process of this method is relatively simple, most of the halogenated hydrocarbons are poisonous, and the hydrogen halide produced in the reaction process needs to be absorbed with an excessive amount of alkali, thus producing a large amount of three wastes (USA Segeruo Company patent CN1409699A). Another method is to start from alcohols, form aldehydes or ketones through dehydrogenation, condense aldehydes or ketones with primary amines to form imines, and then reduce the imines with hydrogen to prepare a three-step process for secondary amines (Kao Corporation patent CN101331109A). This method has had a relatively mature production technology process, such as U.S. Patent No. 3994975, which reports a method in a hydrogen atmosphere under the catalysis of a supported metal catalyst (5% Pd/C and 5% Pt/C) and Raney-Ni. Process for preparing secondary and tertiary amines by reductive amination of saturated cyclic ketones. Under relatively high hydrogen pressure, heterogeneous multicomponent copper-based catalysts can be used to prepare organic amines by catalyzing the reaction of aldehydes or ketones or primary or secondary alcohols with ammonia, primary amines or secondary amines (BASF patents CN1984873A, CN1123789A and CN101208319A). Chinese patent CN1671646 provides a method for preparing secondary amines by reacting primary amines with alkylating reagent aldehydes or ketones and high-pressure hydrogen in the presence of a supported palladium catalyst. Under high temperature conditions, the heterogeneous three-component Ni-Ru-Pd catalyst catalyzes the reaction of alcohols, aldehydes or ketones with ammonia, primary or secondary amines or acetonitrile to produce amines (BP company patent CN88101658A). Catalytic hydrogenation reduction of nitriles (BASF patents CN1365965A, CN1367164A) and nitro compounds (CN1939890A) are also used to prepare organic amines.

In the above-mentioned reaction process involving the preparation of organic amines by catalytic hydrogenation, the hydrogen pressure is often high, and the production and operation safety hazards are large, and a mixture containing secondary and tertiary amines is usually obtained. In addition, although the three-stage process technology using alcohol and primary or secondary amines as raw materials is still being used, its defects are very obvious: first, the aldehydes and ketones used as raw materials are obtained by oxidative dehydrogenation of alcohols; Use high-pressure hydrogen, as a flammable and explosive gas, hydrogen has a high risk in the production process, which is not conducive to actual production operations; in the production process, dehydrogenation is first, then aldehydes or ketones are condensed with amines, and then catalytic hydrogenation The process increases energy consumption and correspondingly increases production costs.

Contents of the invention

The present invention aims to solve the above-mentioned deficiencies in the prior art, and provides a method for preparing secondary or tertiary amines in one step directly using alcohols and amines as raw materials. The present invention omits the steps of dehydrogenating alcohols to form aldehydes or ketones in the prior art, or condensing aldehydes or ketones with amines to form imines, and then catalytically hydrogenating and reducing them, which not only reduces the cost of raw materials, but also avoids the use of flammable and explosive Hydrogen reduces the risk factor of production and also reduces the cost of process operation. The invention has easy-to-obtain raw materials, simple process, high product yield, no three wastes and low production cost, and is a method for preparing secondary or tertiary amines with extremely high atom economy and environmental friendliness. At the same time, the heterogeneous catalyst used in the present invention has been commercially produced, and can be recycled for many times after simple treatment, which is also very beneficial to industrial production.

The method for preparing secondary amines and tertiary amines provided by the present invention is realized by a one-step reaction, that is: the reaction raw materials primary alcohol or secondary alcohol, primary amine or secondary amine and catalyst are added to the reactor, and then an organic solvent (or no organic solvent is required) is added. solvent), nitrogen replacement reaction system, closed reactor; stirring reaction at 80-200 ° C for 1-24 hours, high conversion rate and high selectivity to generate the corresponding secondary or tertiary amine, the crude product is distilled under reduced pressure or heavy Crystallization and other methods can be used to obtain high-purity secondary or tertiary amine products.

The catalyst is a heterogeneous bimetallic platinum-tin (Pt-Sn) catalyst immobilized on the inorganic material γ-Al ₂ O ₃ or TiO ₂ , and the catalyst is a heterogeneous bimetallic platinum-tin catalyst Pt-Sn/γ- Al ₂ O ₃ or Pt-Sn/TiO ₂ , the mass percentage of platinum in the catalyst is 0.1-10%, and the molar ratio of platinum to tin is 1:1-1:11. The heterogeneous bimetallic platinum-tin catalyst described therein is firstly applied to the reaction of preparing secondary and tertiary amines from primary or secondary alcohols and nitrogen-containing compounds selected from primary or secondary amines.

The catalyst can be prepared by applying a catalytically active metal and an additional metal to an inorganic material carrier; the catalytically active metal is platinum, the additional metal is tin, and the inorganic material carrier is aluminum oxide (γ-Al ₂ O ₃ ) or titanium dioxide (TiO ₂ ).

Specifically describe the method that the present invention prepares secondary amine and tertiary amine as:

1) the preparation method of described secondary amine is to be primary alcohol described in formula I or secondary alcohol and the primary amine described in formula II, with 1: 1-1.1: 1 molar ratio in closed reactor, in organic solvent ( or no organic solvent) and the presence of a catalyst, stirring and heating to 80-200°C for 1-24 hours to generate a crude secondary amine. The crude product was separated and purified to obtain the secondary amine product III (reaction formula 1).

In primary or secondary alcohol I, R is an alkyl group with 1-20 carbon atoms, benzyl, substituted benzyl C ₆ H _5-a X _a CH ₂ , or a five-membered or four-membered heterocyclic functional group Methyl C ₅ H _4-b YX _b CH ₂ , C ₄ H _3-c YX _c CH ₂ ; wherein: a is an integer of 1-5, b is an integer of 0-4, and c is an integer of 0-3; Y is N or O or S; X is hydrogen, or an alkyl group with 1-4 carbon atoms, an alkoxy group, or a halogen atom. Wherein R is preferably benzyl, substituted benzyl (the group whose aryl is mono- or multi-substituted is preferably methyl, ethyl, isopropyl, (tert) butyl, methoxy, chlorine, bromine or iodine atom) or An alkyl group having 1 to 20 carbon atoms.

In primary amine II, R ¹ is aryl C ₆ H _5-a X _a , benzyl, naphthyl or heterocyclic aryl C ₅ H _4-b YX _b ; wherein a is an integer of 0-5, b is An integer of 0-4; Y is N; X is hydrogen, or an alkyl, alkoxy or halogen atom with 1-4 carbon atoms. wherein ^R is preferably an aryl group (wherein the aryl group is mono- or polysubstituted preferably a methyl, ethyl, isopropyl, (tert)butyl, methoxy, chlorine, bromine or iodine atom).

2) The preparation method of the tertiary amine is to use the primary alcohol or secondary alcohol described in formula I and the primary amine described in formula II, in a closed reactor with n: 1 molar ratio (n=2-20), in In the presence of an organic solvent (or no organic solvent) and a catalyst, stir and heat to 80-200° C. for 1-24 hours to generate a crude tertiary amine product. The crude product was separated and purified to obtain the tertiary amine product IV (reaction formula 2).

In primary or secondary alcohol I, R is an alkyl group with 1-20 carbon atoms, benzyl, substituted benzyl C ₆ H _5-a X _a CH ₂ , or a five-membered or four-membered heterocyclic functional group Methyl C ₅ H _4-b YX _b CH ₂ , C ₄ H _3-c YX _c CH ₂ ; wherein: a is an integer of 1-5, b is an integer of 0-4, and c is an integer of 0-3; Y is N or O or S; X is hydrogen, or an alkyl group with 1-4 carbon atoms, an alkoxy group, or a halogen atom. Wherein R is preferably benzyl, substituted benzyl (the group whose aryl is mono- or multi-substituted is preferably methyl, ethyl, isopropyl, (tert) butyl, methoxy, chlorine, bromine or iodine atom) or An alkyl group having 1 to 20 carbon atoms.

In primary amine II, R ¹ is aryl C ₆ H _5-a X _a , benzyl, naphthyl or heterocyclic aryl C ₅ H _4-b YX _b ; wherein a is an integer of 0-5, b is An integer of 0-4; Y is N; X is hydrogen, or an alkyl, alkoxy or halogen atom with 1-4 carbon atoms. wherein ^R is preferably an aryl group (wherein the aryl group is mono- or polysubstituted preferably a methyl, ethyl, isopropyl, (tert)butyl, methoxy, chlorine, bromine or iodine atom).

3) The preparation method of the tertiary amine is to use the primary alcohol or secondary alcohol described in formula I and the secondary amine described in formula V in a closed reactor in a molar ratio of n:1 (n=1-20), In the presence of an organic solvent and a catalyst, stir and heat to 80-200°C for 1-24 hours to generate a crude tertiary amine product. The crude product was separated and purified to obtain the tertiary amine product VI (reaction formula 3).

In primary or secondary alcohol I, R is an alkyl group with 1-20 carbon atoms, benzyl, substituted benzyl C ₆ H _5-a X _a CH ₂ , or a five-membered or four-membered heterocyclic functional group Methyl C ₅ H _4-b YX _b CH ₂ , C ₄ H _3-c YX _c CH ₂ ; wherein: a is an integer of 1-5, b is an integer of 0-4, and c is an integer of 0-3; Y is N or O or S; X is hydrogen, or an alkyl group with 1-4 carbon atoms, an alkoxy group, or a halogen atom. Wherein R is preferably benzyl, substituted benzyl (the group whose aryl is mono- or multi-substituted is preferably methyl, ethyl, isopropyl, (tert) butyl, methoxy, chlorine, bromine or iodine atom) or An alkyl group having 1 to 20 carbon atoms.

In the secondary amine V, R ¹ and R ² are alkyl, benzyl or substituted benzyl C ₆ H _5-a X _a CH ₂ with 1-20 carbon atoms, wherein a is an integer of 1-5, and X is Hydrogen, an alkyl or alkoxy group with 1 to 4 carbon atoms, or a halogen atom. R ¹ and R ² are preferably benzyl or an alkyl group with 1-20 carbon atoms, wherein R ¹ and R ² together may also be preferably a cycloalkyl group with 3-10 carbon atoms.

4) The preparation of the tertiary amine is to use the dibasic primary alcohol or secondary alcohol described in the formula VII and the primary amine described in the formula II as raw materials, by n: 1 molar ratio, n=1-10, in a closed reaction In the container, in the solution and in the presence of a catalyst, stirring and heating to 80-200°C for 1-24 hours to obtain the tertiary amine product VIII (reaction formula 4);

In the dihydric primary or secondary alcohol VII, R ³ is a straight chain or branched chain alkyl disubstituted by two hydroxyl groups with 3-14 carbon atoms. In tertiary amine VIII, ^R3 is double substituted by a nitrogen atom.

In primary amine II, R ¹ is aryl C ₆ H _5-a X _a , benzyl C ₆ H _5-a X _a CH ₂ , naphthyl or heterocyclic aryl C ₅ H _4-b YX _b ; wherein a is an integer of 0-5, b is an integer of 0-4; Y is N; X is hydrogen, or an alkyl group with 1-4 carbon atoms, an alkoxy group with 1-4 carbon atoms or a halogen atom ; R ¹ is preferably aryl.

The catalyst described in the present invention is a heterogeneous bimetallic platinum-tin catalyst, and the two metals are immobilized on the inorganic material carrier γ-Al ₂ O ₃ or TiO ₂ , wherein the mass percentage of metal platinum is 0.1-10%, and platinum The molar ratio of Pt:Sn to tin is 1:1-11:1.

The amount of catalyst used is based on the amount of platinum used, and the molar ratio of platinum to amine reactants is 0.01:100-5:100, preferably 0.25:100.

Described solvent is inert solvents such as toluene, xylene and mesitylene, and preferred organic solvent is xylene.

In the preparation method of the organic amine, the reaction of the alcohol and the amine is carried out in a closed reactor under a nitrogen atmosphere, and the initial pressure of the nitrogen is 1 atmosphere.

In the preparation method of organic amine, the reaction between alcohol and amine is carried out at 80-200°C, and the effect is best at 120-150°C.

Compared with the existing methods for preparing secondary and tertiary amines, the present invention has the following advantages: easy to obtain raw materials, simple process, high product yield, no three wastes, low production cost, etc., and is a very high atom economy , Environmentally friendly method for preparing secondary and tertiary amines. The heterogeneous catalyst used has been commercialized, and can be recycled for many times after simple treatment, which is very beneficial to industrial production, so the invention has broad application prospects.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto.

Embodiment 1: the preparation of N-phenylbenzylamine

In a 15mL sealable reaction tube, add benzyl alcohol (108mg, 1mmol), aniline (93mg, 1mmol), catalyst Pt-Sn/γ-Al ₂ O ₃ (100mg) (wherein the mass percentage of Pt is 0.5%, metal The molar ratio of Pt to Sn is 1:3), xylene (5 mL) and a magneton for stirring, and after the reaction system was replaced with nitrogen, the reaction tube was closed. The oil bath was heated to 150°C, and the reaction was stirred for 8 hours. Gas chromatographic analysis showed that the conversion of aniline was complete, the reaction mixture was centrifuged to remove the catalyst, and the recovered catalyst was recycled. Silica gel column chromatography (flushing agent is petroleum ether: ethyl acetate = 20: 1, product R _f = 0.6), the product was confirmed by NMR and high-resolution mass spectrometry, and N-phenylbenzylamine was obtained in a yield of 97 %.

Embodiment 2: the preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, except that the difference from Example 1 is that the molar ratio of metal Pt to Sn in the catalyst Pt-Sn/γ-Al ₂ O ₃ is 1:1, and the product is tested by NMR and high-resolution mass spectrometry. Determination confirmed that the target product N-phenylbenzylamine was obtained with a yield of 80%.

Embodiment 3: the preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, except that the difference from Example 1 is that the molar ratio of metal Pt to Sn in the catalyst Pt-Sn/γ-Al ₂ O ₃ is 1:2, and the product is tested by NMR and high-resolution mass spectrometry. Determination confirmed that the target product N-phenylbenzylamine was obtained with a yield of 93%.

Embodiment 4: the preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the metal Pt and Sn molar ratio in the catalyst Pt-Sn/γ-Al ₂ O ₃ used is 1:5, and the product is determined by NMR and high-resolution mass spectrometry It was confirmed that the target product N-phenylbenzylamine was obtained with a yield of 94%.

Embodiment 5: the preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the molar ratio of metal Pt to Sn in the catalyst Pt-Sn/γ-Al ₂ O ₃ used is 1:7, and the product is determined by NMR and high-resolution mass spectrometry It was confirmed that the target product N-phenylbenzylamine was obtained with a yield of 94%.

Embodiment 6: the preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the metal Pt and Sn molar ratio in the catalyst Pt-Sn/γ-Al ₂ O ₃ used is 1:9, and the product is determined by NMR and high-resolution mass spectrometry It was confirmed that the target product N-phenylbenzylamine was obtained with a yield of 91%.

Embodiment 7: the preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, except that the molar ratio of metal Pt to Sn in the catalyst Pt-Sn/γ-Al ₂ O ₃ used is 1:11, and the product is determined by NMR and high-resolution mass spectrometry It was confirmed that the target product N-phenylbenzylamine was obtained with a yield of 93%.

Embodiment 8: Preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the catalyst used is Pt-Sn/TiO ₂ (100mg) (wherein the mass percentage of Pt is 0.5%, and the molar ratio of metal Pt to Sn is 1:3 ). According to gas chromatography, the conversion of aniline was 64%, and the reaction mixture was centrifuged to remove the catalyst. Silica gel column chromatography (flushing agent is petroleum ether: ethyl acetate = 20: 1, product R _f = 0.6), the product was confirmed by NMR and high-resolution mass spectrometry, and N-phenylbenzylamine was obtained in a yield of 55 %.

Embodiment 9: Preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the catalyst used is Pt-Sn/TiO ₂ (100mg) (wherein the mass percentage of Pt is 0.5%, and the molar ratio of metal Pt to Sn is 1:3 ), the reaction time is 24 hours. According to gas chromatography analysis, the conversion rate of aniline was 95%, and the reaction mixture was centrifuged to remove the catalyst. Silica gel column chromatography (flushing agent: petroleum ether: ethyl acetate = 20:1), the product was confirmed by NMR and high-resolution mass spectrometry to obtain N-phenylbenzylamine with a yield of 85%.

Embodiment 10: Preparation of N-phenylbenzylamine

The reaction steps were the same as in Example 1, except that the reaction temperature was 80° C., and the product was confirmed by NMR and high-resolution mass spectrometry to obtain N-phenylbenzylamine with a yield of 20%.

Embodiment 11: Preparation of N-phenylbenzylamine

The reaction steps were the same as in Example 1, except that the reaction temperature was 200° C., and the product was confirmed by NMR and high-resolution mass spectrometry to obtain N-phenylbenzylamine with a yield of 85%.

Embodiment 12: Preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the catalyst used is used for the second time after recovery, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain N-phenylbenzylamine with a yield of 96%. .

Embodiment 13: Preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the catalyst used is used for the third time after recovery, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain N-phenylbenzylamine with a yield of 95%. .

Embodiment 14: Preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the catalyst used is used for the fourth time after recovery, and the reaction time is 24 hours. The product is confirmed by NMR and high-resolution mass spectrometry to obtain N-phenylbenzylamine , yield 94%.

Embodiment 15: Preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1. The difference from Example 1 is that the amount of benzyl alcohol is 432mg (4mmol), the amount of aniline is 372mg (4mmol), and the amount of catalyst is 400mg. The product is confirmed by NMR and high-resolution mass spectrometry to obtain N- Phenylbenzylamine, yield 98%.

Embodiment 16: Preparation of N-(2-methylphenyl)benzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is 2-methylaniline (107mg, 1mmol), heated and stirred for 24 hours, and the product was confirmed by NMR and high-resolution mass spectrometry to obtain the target The product N-(2-methylphenyl)benzylamine has a yield of 91%.

Embodiment 17: Preparation of N-(3-methylphenyl)benzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is 3-methylaniline (107mg, 1mmol), heated and stirred for 8 hours, and the product was confirmed by NMR and high-resolution mass spectrometry to obtain the target The product N-(3-methylphenyl)benzylamine has a yield of 93%.

Embodiment 18: Preparation of N-(4-methylphenyl)benzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is 4-methylaniline (107mg, 1mmol), heated and stirred for 8 hours, and the product was confirmed by NMR and high-resolution mass spectrometry to obtain the target The product N-(4-methylphenyl)benzylamine, the yield is 90%.

Embodiment 19: Preparation of N-(3,5-dimethylphenyl)benzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is 3,5-dimethylaniline (121mg, 1mmol), heated and stirred for 10 hours, and the product was confirmed by NMR and high-resolution mass spectrometry , to obtain the target product N-(3,5-dimethylphenyl)benzylamine with a yield of 94%.

Embodiment 20: Preparation of N-(2-chlorophenyl)benzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is 2-chloroaniline (127 mg, 1 mmol), heated and stirred for 24 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain the target product N-(2-chlorophenyl)benzylamine, yield 87%.

Example 21: Preparation of N-(3-chlorophenyl)benzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is 3-chloroaniline (127 mg, 1 mmol), heated and stirred for 8 hours, heated and stirred for 24 hours, and the product was tested by NMR and high-resolution mass spectrometry. Determination confirmed that the target product N-(3-chlorophenyl)benzylamine was obtained with a yield of 95%.

Example 22: Preparation of N-(4-chlorophenyl)benzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is 4-chloroaniline (127mg, 1mmol), heated and stirred for 8 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain the target product N-(4-chlorophenyl)benzylamine, yield 92%.

Example 23: Preparation of N-(3,5-dichlorophenyl)benzylamine

The reaction steps are the same as in Example 1. The difference from Example 1 is that the amine used is 3,5-dichloroaniline (161mg, 1mmol), heated and stirred for 8 hours, and the product was confirmed by NMR and high-resolution mass spectrometry. The target product N-(3,5-dichlorophenyl)benzylamine was obtained with a yield of 85%.

Example 24: Preparation of N-(1-naphthyl)benzylamine

The reaction steps are the same as in Example 1, except that the amine used is 1-naphthylamine (143mg, 1mmol), heated and stirred for 24 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain the target product N-(1-naphthyl)benzylamine, yield 83%.

Embodiment 25: Preparation of dibenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is benzylamine (107mg, 1mmol), heated and stirred for 8 hours, and the product is confirmed by NMR and high-resolution mass spectrometry, and the target product dibenzylamine is obtained. Amine, yield 92%.

Example 26: Preparation of N-cyclohexylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is cyclohexylamine (99mg, 1mmol), heated and stirred for 24 hours, and the product was confirmed by NMR and high-resolution mass spectrometry to obtain the target product N -Cyclohexylbenzylamine, yield 83%.

Example 27: Preparation of N-(2-pyridyl)benzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is 2-aminopyridine (94mg, 1mmol), heated and stirred for 24 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain the target product N-(2-pyridyl)benzylamine, the yield is 99%.

Example 28: Preparation of N-(2-pyridylmethyl)benzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is 2-pyridylmethylamine (109mg, 1mmol), 200mg of catalyst consumption and 24 hours of reaction time, and the product is determined by NMR and high-resolution mass spectrometry It was confirmed that the target product N-(2-pyridylmethyl)benzylamine was obtained with a yield of 70%.

Example 29: Preparation of N-(4-methoxybenzyl)aniline

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the alcohol used is 4-methoxybenzyl alcohol (138mg, 1mmol), the reaction time is 24 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain The target product N-(4-methoxybenzyl)aniline, the yield is 93%.

Example 30: Preparation of N-(4-chlorobenzyl)aniline

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the alcohol used is 4-chlorobenzyl alcohol (142mg, 1mmol), the reaction time is 24 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain the target product N-(4-chlorobenzyl)aniline, the yield is 90%.

Example 31: Preparation of N-(3-chlorobenzyl)aniline

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the alcohol used is 3-chlorobenzyl alcohol (142mg, 1mmol), the reaction time is 24 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain the target product N-(3-chlorobenzyl)aniline, yield 93%.

Example 32: Preparation of N-(2-chlorobenzyl)aniline

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the alcohol used is 2-chlorobenzyl alcohol (142mg, 1mmol), the reaction time is 24 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain the target product N-(2-chlorobenzyl)aniline, the yield is 90%.

Example 33: Preparation of N-(2-phenylethyl)aniline

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the alcohol used is 2-phenylethanol (122mg, 1mmol), the reaction time is 24 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain the target product N -(2-Phenylethyl)aniline, yield 88%.

Example 34: Preparation of N-(2-(2-fluorophenyl)ethyl)aniline

The reaction steps are the same as in Example 1, except that the alcohol used is 2-(2-fluorophenyl)ethanol (140mg, 1mmol), heated and stirred for 24 hours to obtain the target product N-(2-( 2-fluorophenyl) ethyl) aniline, the product was confirmed by nuclear magnetic resonance spectrum and high-resolution mass spectrum, and the yield was 70%. NMR data of N-(2-(2-fluorophenyl)ethyl)aniline: ¹ H NMR (CDCl ₃ , 400MHz) δ7.33(m, 4H, aryl CH), 7.17(m, 2H, aryl CH), 6.85 (t, 1H, aryl CH), 6.74 (m, 2H, aryl CH), 3.82 (s, 1H, NH), 3.48 (t, 2H, N-CH ₂ ), 3.04 ( t, 2H, CH ₂ -aryl). ¹³ C{ ¹ H} NMR (100MHz, CDCl ₃ ) δ 162.6 (Cq, CF), 160.2 (Cq, CN), 147.9 (Cq), 131.1 (d, J = 3.7Hz), 129.4, 128.2 (d, J = 7.8Hz), 126.3 (d, J = 16.0Hz), 117.5, 115.3 (d, J = 21.9Hz) and 112.9 (aryl CH), 43.8 (CH ₂ N), 29.2( _CH2 -aryl). Calculated molecular weight: 215.1110; measured value by high resolution mass spectrometry: 215.1116.

Example 35: Preparation of N-(2-(3-fluorophenyl)ethyl)aniline

The reaction steps are the same as in Example 1, except that the alcohol used is 2-(3-fluorophenyl)ethanol (140mg, 1mmol), heated and stirred for 24 hours to obtain the target product N-(2-( 3-fluorophenyl) ethyl) aniline, the product was confirmed by nuclear magnetic resonance spectrum and high-resolution mass spectrum, and the yield was 70%. NMR data of N-(2-(3-fluorophenyl)ethyl)aniline: ¹ H NMR (CDCl ₃ , 400MHz) δ7.35(m, 1H, aryl CH), 7.28(t, 2H, aryl CH), 7.08 (d, J = 7.6 Hz, 1H, aryl CH), 7.03 (m, 2H, aryl CH), 6.82 (t, 1H, aryl CH), 6.70 (d, J = 7.9 Hz, 2H, aryl CH), 3.73 (s, 1H, NH), 3.47 (t, 2H, N-CH ₂ ), 2.98 (t, 2H, CH ₂ -aryl). ¹³ C{ ¹ H} NMR (100MHz, CDCl ₃ ) δ164.3(Cq, CF), 161.8(Cq, CN), 147.9(Cq), 130.1(d, J=82.0Hz), 129.4, 124.5, 117.7, 115.7(d, J=20.8 Hz), 113.4 (d, J = 20.9 Hz) and 113.1 (aryl CH), 44.8 ( _CH2N ), 35.3 (CH2 _- aryl). Calculated molecular weight: 215.1110; measured value by high resolution mass spectrometry: 215.1111.

Example 36: Preparation of N-(2-pyridylmethyl)aniline

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the alcohol used is 2-pyridinemethanol (110mg, 1mmol), the catalyst consumption is 400mg, and the reaction time is 24 hours, and the product is confirmed by nuclear magnetic resonance spectrum and high-resolution mass spectrometry, The target product N-(2-pyridylmethyl)aniline was obtained with a yield of 72%.

Example 37: Preparation of N-heptylaniline

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the alcohol used is n-heptanol (116 mg, 1 mmol), heated and stirred for 24 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain the target product N -Heptylaniline, yield 93%.

Example 38: Preparation of N-isopropylaniline

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the alcohol used is isopropanol (60mg, 1mmol), the catalyst consumption is 200mg, and the reaction time is 24 hours. The product is confirmed by NMR and high-resolution mass spectrometry, and obtains The target product N-isopropylaniline, the yield is 92%.

Example 39: Preparation of N-(2-hexyl)aniline

The reaction step is the same as Example 1, and the difference from Example 1 is that the alcohol used is 2-hexanol (102mg, 1mmol), catalyst consumption 200mg, reaction time 24 hours, and the product is confirmed by nuclear magnetic resonance spectrum and high-resolution mass spectrometry, The target product N-(2-hexyl)aniline was obtained with a yield of 85%.

Example 40: Preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amount of benzyl alcohol is 237 mg (2.2 mmol), and the product is confirmed by NMR and high-resolution mass spectrometry to obtain N-phenylbenzylamine with a yield of 90%. .

Example 41: Preparation of N-phenylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amount of benzyl alcohol is 1620mg (15mmol), and the amount of aniline is 1395mg (15mmol). The product is confirmed by NMR and high-resolution mass spectrometry to obtain N-phenyl Benzylamine, yield 58%.

Example 42: Preparation of N-phenylpyrrolidine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the alcohol used is 1,4-butanediol (90mg, 1mmol), the reaction time is 24 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain The target product N-phenylpyrrolidine has a yield of 95%.

Example 43: Preparation of N-phenylpiperidine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the alcohol used is 1,5-pentanediol (104mg, 1mmol), the reaction time is 24 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain The target product, N-phenylpiperidine, has a yield of 85%.

Example 44: Preparation of N-Benzylpiperidine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is piperidine (85mg, 1mmol), and the reaction time is 24 hours to obtain the target product N-benzylpiperidine with a yield of 80%. Confirmation by resonance spectroscopy and high-resolution mass spectrometry.

Example 45: Preparation of N-benzylmorpholine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is morpholine (87mg, 1mmol), the reaction time is 24 hours, and the product is confirmed by NMR and high-resolution mass spectrometry to obtain the target product N-benzyl Base morpholine, yield 95%.

Example 46: Preparation of N, N-diethylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is diethylamine (73mg, 1mmol), the catalyst consumption is 300mg, and the reaction time is 24 hours. The product is confirmed by NMR and high-resolution mass spectrometry, and obtained The target product N,N-diethylbenzylamine, the yield is 75%.

Example 47: Preparation of N,N-dimethylbenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is 33% dimethylamine aqueous solution (154mg, 1.1mmol), the catalyst consumption is 300mg, and the reaction time is 24 hours. As confirmed by mass spectrometry, the target product N,N-dimethylbenzylamine was obtained with a yield of 55%.

Example 48: Preparation of Tribenzylamine

The reaction steps were the same as in Example 1, except that benzyl alcohol (5 mL) and benzylamine (93 mg, 1 mmol) were added, and the organic solvent xylene was not added. The reaction yielded tribenzylamine (petroleum ether:ethyl acetate=20:1, product R _f =0.8), with a yield of 92%, and the product was confirmed by NMR and high-resolution mass spectrometry.

Example 49: Preparation of Tribenzylamine

The reaction steps are the same as in Example 1, and the difference from Example 1 is that the amine used is dibenzylamine (197mg, 1mmol), the catalyst consumption is 200mg, the reaction time is 24 hours, and the product is confirmed by nuclear magnetic resonance spectrum and high-resolution mass spectrometry, The target product tribenzylamine was obtained with a yield of 83%.

Claims (8)

1. a method for preparing secondary amine and tertiary amine, is characterized in that: take primary alcohol or secondary alcohol and primary amine or secondary amine as raw material, in closed reactor by heterogeneous bimetallic platinum-tin catalyst Pt-Sn/ Catalytic dehydration of γ-Al ₂ O ₃ or Pt-Sn/TiO ₂ at 80-200°C to prepare secondary or tertiary amines. 2. The method according to claim 1, characterized in that: the mass percentage of platinum in the catalyst is 0.1-10%, and the molar ratio of platinum to tin is 1:1-1:11. 3. The method of claim 1, wherein:

1) The preparation of the secondary amine is to use the primary alcohol described in formula I or secondary alcohol and the primary amine described in formula II as raw materials, in a closed reactor at a molar ratio of 1:1-1.1:1, in the solution In the presence of a catalyst, stirring and heating to 80-200 ° C for 1-24 hours to obtain the secondary amine product III (reaction formula 1); In primary or secondary alcohol I, R is an alkyl group with 1-20 carbon atoms, benzyl C ₆ H _5-a X _a CH ₂ , or methyl C ₅ with a five-membered or four-membered heterocyclic functional group One of H _4-b YX _b CH ₂ and C ₄ H _3-c YX _c CH ₂ ; wherein: a is an integer of 0-5, b is an integer of 0-4, c is an integer of 0-3; Y is N or O or S; X is hydrogen, or an alkyl group with 1-4 carbon atoms, an alkoxy group with 1-4 carbon atoms, or a halogen atom; In primary amine II, R ¹ is aryl C ₆ H _5-a X _a , benzyl C ₆ H _5-a X _a CH ₂ , naphthyl or heterocyclic aryl C ₅ H _4-b YX _b ; wherein a is an integer of 0-5, b is an integer of 0-4; Y is N; X is hydrogen, or an alkyl group with 1-4 carbon atoms, an alkoxy group with 1-4 carbon atoms or a halogen atom ; Or, 2) the preparation of the tertiary amine is to use the primary alcohol or secondary alcohol described in formula I and the primary amine described in formula II as raw materials, according to n:1 molar ratio, n=2-20, in a closed reaction In the container, in the solution and in the presence of a catalyst, stir and heat to 80-200 ° C for 1-24 hours to obtain the tertiary amine product IV (reaction formula 2); In primary or secondary alcohol I, R is an alkyl group with 1-20 carbon atoms, benzyl C ₆ H _5-a X _a CH ₂ , or methyl C ₅ with a five-membered or four-membered heterocyclic functional group One of H _4-b YX _b CH ₂ and C ₄ H _3-c YX _c CH ₂ ; wherein: a is an integer of 0-5, b is an integer of 0-4, c is an integer of 0-3; Y is N or O or S; X is hydrogen, or an alkyl group with 1-4 carbon atoms, an alkoxy group with 1-4 carbon atoms, or a halogen atom; In primary amine II, R ¹ is aryl C ₆ H _5-a X _a , benzyl C ₆ H _5-a X _a CH ₂ , naphthyl or heterocyclic aryl C ₅ H _4-b YX _b ; wherein a is an integer of 0-5, b is an integer of 0-4; Y is N; X is hydrogen, or an alkyl group with 1-4 carbon atoms, an alkoxy group with 1-4 carbon atoms or a halogen atom ; Or, 3) the preparation of the tertiary amine is to use the primary alcohol or secondary alcohol described in formula I and the secondary amine described in formula V, according to n:1 molar ratio, n=1-20, in a closed reactor , in the solution, in the presence of a catalyst, stirring and heating to 80-200 ° C for 1-24 hours to obtain the tertiary amine product VI (reaction formula 3); In primary or secondary alcohol I, R is an alkyl group with 1-20 carbon atoms, benzyl C ₆ H _5-a X _a CH ₂ , or methyl C ₅ with a five-membered or four-membered heterocyclic functional group One of H _4-b YX _b CH ₂ and C ₄ H _3-c YX _c CH ₂ ; wherein: a is an integer of 0-5, b is an integer of 0-4, c is an integer of 0-3; Y is N or O or S; X is hydrogen, or an alkyl group with 1-4 carbon atoms, an alkoxy group with 1-4 carbon atoms, or a halogen atom; In the secondary amine V, R ¹ and R ² are alkyl groups with 1-20 carbon atoms, benzyl C ₆ H _5-a X _a CH ₂ , where a is an integer of 0-5, X is hydrogen, carbon atoms An alkyl group with 1-4 carbon atoms or an alkoxy group with 1-4 carbon atoms or a halogen atom; Or, 4) the preparation of the tertiary amine is to use the dibasic primary alcohol or secondary alcohol described in the formula VII and the primary amine described in the formula II as raw materials, according to n:1 molar ratio, n=1-10, in In a closed reactor, in the solution and in the presence of a catalyst, stirring and heating to 80-200 ° C for 1-24 hours to obtain the tertiary amine product VIII (reaction formula 4); In dihydric primary or secondary alcohol VII, R ³ is a straight chain or branched chain alkyl disubstituted by two hydroxyl groups with 3-14 carbon atoms; in tertiary amine VIII, R ³ is double substituted by nitrogen atom; In primary amine II, R ¹ is one of aryl C ₆ H _5-a X _a , benzyl C ₆ H _5-a X _a CH ₂ , naphthyl or heterocyclic aryl C ₅ H _4-b YX _b ; wherein a is an integer of 0-5, b is an integer of 0-4; Y is N; X is hydrogen, or an alkyl group with 1-4 carbon atoms, an alkoxy group with 1-4 carbon atoms or halogen atom. 4. The method of claim 3, wherein: The molar ratio of I and II described in step 1) is preferably 1:1; Wherein R is preferably benzyl, substituted benzyl or an alkyl group with 1-20 carbon atoms, and the aryl group in substituted benzyl is preferably methyl, ethyl, isopropyl, (tert) butyl radical, methoxy, chlorine, bromine or iodine atom; Wherein ^R is preferably an aryl group, wherein the aryl group is preferably a methyl, ethyl, isopropyl, (tert)butyl, methoxy, chlorine, bromine or iodine atom by a mono- or multi-substituted group; The molar ratio of I and II described in step 2) is preferably 2:1; Wherein R is preferably benzyl, substituted benzyl or an alkyl group with 1-20 carbon atoms, and the aryl group in substituted benzyl is preferably methyl, ethyl, isopropyl, (tert) butyl radical, methoxy, chlorine, bromine or iodine atom; Wherein ^R is preferably an aryl group, wherein the aryl group is preferably a methyl, ethyl, isopropyl, (tert)butyl, methoxy, chlorine, bromine or iodine atom by a mono- or multi-substituted group; The molar ratio of I and V described in step 3) is preferably 1:1; Wherein R is preferably benzyl, substituted benzyl or an alkyl group with 1-20 carbon atoms, and the aryl group in substituted benzyl is preferably methyl, ethyl, isopropyl, (tert) butyl radical, methoxy, chlorine, bromine or iodine atom; R ¹ and R ² are preferably benzyl or an alkyl group with 1-20 carbon atoms, wherein R ¹ and R ² together may also be preferably a cycloalkyl group with 3-10 carbon atoms; The molar ratio of II and VII described in step 4) is preferably 1:1; Wherein ^R3 is preferably a linear alkyl disubstituted by two hydroxyl groups with 3-10 carbon atoms. In tertiary amine VIII, R ³ is double substituted by nitrogen atom; R ¹ is preferably aryl C ₆ H _5-a X _a , naphthyl or heterocyclic aryl C ₅ H _4-b YX _b ; wherein a is an integer of 0-5, b is an integer of 0-4; Y is N ; X is hydrogen, or an alkyl group with 1-4 carbon atoms, an alkoxy group with 1-4 carbon atoms or a halogen atom; R ¹ is preferably an aryl group. 5. The method according to claim 3, characterized in that: said solution refers to the liquid phase system formed by adding an organic solvent as a reaction medium in the liquid phase reaction raw material or in the reactor; The reaction medium is one or more of the inert organic solvents toluene, xylene and trimethylbenzene, preferably the organic solvent is xylene. 6. The method according to any one of claims 1-5, characterized in that: the catalyst consumption is based on platinum consumption, and the molar ratio of platinum and amine reactants is 0.01: 100-5: 100, and the reaction The temperature is 120-150°C. 7. The method according to claim 6, characterized in that: the molar ratio of platinum to amine reactants is 0.25:100. 8. The method according to any one of claims 1-7, characterized in that: the reaction atmosphere is nitrogen, and its initial pressure is 1 atmosphere.